fix(codecs): coerce cid.Undef to null in dag{json,cbor} output

Otherwise we end up with invalid output. dag-cbor: 0xd82a4100 d8 2a # tag(42) 41 # bytes(1) 00 # "\x00" dag-json: {"/":"b"} Fixes: #246
ipld · Jun 1, 2022 · eb767ed · eb767ed
1 parent 651b1cd
commit eb767ed
Show file tree

Hide file tree

Showing 4 changed files with 47 additions and 0 deletions.
diff --git a/codec/dagcbor/marshal.go b/codec/dagcbor/marshal.go
@@ -144,6 +144,9 @@ func marshal(n datamodel.Node, tk *tok.Token, sink shared.TokenSink, options Enc
 		}
 		switch lnk := v.(type) {
 		case cidlink.Link:
+			if !lnk.Cid.Defined() {
+				return fmt.Errorf("encoding undefined CIDs are not supported by this codec")
+			}
 			tk.Type = tok.TBytes
 			tk.Bytes = append([]byte{0}, lnk.Bytes()...)
 			tk.Tagged = true

diff --git a/codec/dagcbor/marshal_test.go b/codec/dagcbor/marshal_test.go
@@ -7,7 +7,11 @@ import (
 	"time"
 
 	qt "github.com/frankban/quicktest"
+	"github.com/ipfs/go-cid"
+	"github.com/ipld/go-ipld-prime"
 	"github.com/ipld/go-ipld-prime/datamodel"
+	"github.com/ipld/go-ipld-prime/fluent/qp"
+	cidlink "github.com/ipld/go-ipld-prime/linking/cid"
 	basicnode "github.com/ipld/go-ipld-prime/node/basic"
 	"github.com/ipld/go-ipld-prime/testutil/garbage"
 )
@@ -68,3 +72,15 @@ func TestEncodedLength(t *testing.T) {
 		}
 	})
 }
+
+func TestMarshalUndefCid(t *testing.T) {
+	link, err := cid.Decode("bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi")
+	qt.Assert(t, err, qt.IsNil)
+	node, err := qp.BuildMap(basicnode.Prototype.Any, -1, func(ma datamodel.MapAssembler) {
+		qp.MapEntry(ma, "UndefCid", qp.Link(cidlink.Link{Cid: cid.Undef}))
+		qp.MapEntry(ma, "DefCid", qp.Link(cidlink.Link{Cid: link}))
+	})
+	qt.Assert(t, err, qt.IsNil)
+	_, err = ipld.Encode(node, Encode)
+	qt.Assert(t, err, qt.ErrorMatches, "encoding undefined CIDs are not supported by this codec")
+}
diff --git a/codec/dagjson/marshal.go b/codec/dagjson/marshal.go
@@ -257,6 +257,9 @@ func Marshal(n datamodel.Node, sink shared.TokenSink, options EncodeOptions) err
 		}
 		switch lnk := v.(type) {
 		case cidlink.Link:
+			if !lnk.Cid.Defined() {
+				return fmt.Errorf("encoding undefined CIDs are not supported by this codec")
+			}
 			// Precisely four tokens to emit:
 			tk.Type = tok.TMapOpen
 			tk.Length = 1

diff --git a/codec/dagjson/marshal_test.go b/codec/dagjson/marshal_test.go
@@ -0,0 +1,25 @@
+package dagjson
+
+import (
+	"testing"
+
+	qt "github.com/frankban/quicktest"
+	cid "github.com/ipfs/go-cid"
+	"github.com/ipld/go-ipld-prime"
+	"github.com/ipld/go-ipld-prime/datamodel"
+	"github.com/ipld/go-ipld-prime/fluent/qp"
+	cidlink "github.com/ipld/go-ipld-prime/linking/cid"
+	"github.com/ipld/go-ipld-prime/node/basicnode"
+)
+
+func TestMarshalUndefCid(t *testing.T) {
+	link, err := cid.Decode("bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi")
+	qt.Assert(t, err, qt.IsNil)
+	node, err := qp.BuildMap(basicnode.Prototype.Any, -1, func(ma datamodel.MapAssembler) {
+		qp.MapEntry(ma, "UndefCid", qp.Link(cidlink.Link{Cid: cid.Undef}))
+		qp.MapEntry(ma, "DefCid", qp.Link(cidlink.Link{Cid: link}))
+	})
+	qt.Assert(t, err, qt.IsNil)
+	_, err = ipld.Encode(node, Encode)
+	qt.Assert(t, err, qt.ErrorMatches, "encoding undefined CIDs are not supported by this codec")
+}